1. Field of the Invention
The present invention relates to a technique for generating and printing an image including a copy-forgery-inhibited pattern image that deters the use of duplicates and the like.
2. Description of the Related Art
Content such as official forms, certificates of residence, and so on are conventionally printed onto paper that has undergone a special printing process, known as anti-counterfeit paper, for the purpose of prohibiting or suppressing the duplication of such content. With such anti-counterfeit paper, characters reading “copying prohibited” or the like, which are nearly unrecognizable to humans in the original form, appear when the form is duplicated using a copy machine or the like. This has the effect of making the person who duplicated the form hesitant to use that duplicate. Furthermore, the fact that content such as official forms is printed on anti-counterfeit paper alone has the effect of suppressing/deterring duplication itself.
However, such anti-counterfeit paper is problematic in that it has a higher cast than normal paper. This anti-counterfeit paper furthermore is limited in its applications, as only the characters that were set when the anti-counterfeit paper was first manufactured can appear as a result of duplication. Thus, such anti-counterfeit paper lacks flexibility in terms of applications.
Meanwhile, at present, various types of content are being digitized, and the above-mentioned content such as official forms, certificates of residence, and so on are being digitized in a similar manner. Nevertheless, the digitization of such official forms, certificates of residence, and so on is still in a transitional period, and using a printer or the like to output content created using a computer onto paper and using the content is still common.
In response to this situation, a technique has been proposed in which anti-counterfeit paper conventionally created in advance through printing plates is instead generated using a computer and a printer (for example, Japanese Patent Laid-Open No. 2001-197297). This technique generates image data known as a “copy-forgery-inhibited pattern” in addition to the data of the content, superimposes the one data on the other, and outputs the resultant, when printing/outputting content created using a computer. This copy-forgery-inhibited pattern is also sometimes called a copy-deterrent design. Although the copy-forgery-inhibited pattern image looks like nothing more than a simple pattern or background image to the human eye in the original document (the printed material outputted by a printer), predetermined characters or images are visualized when the document is duplicated. Therefore, this original document can provide deterrent effects similar to those of the anti-counterfeit paper mentioned above. This has been made possible by dramatic increases in printer performance.
It goes without saying that normal printing paper can be used for output when superimposing a copy-forgery-inhibited pattern image created using a computer onto content data and outputting the resultant. Such a system is therefore advantageous in terms of cost as compared to using anti-counterfeit paper created in advance. Furthermore, the copy-forgery-inhibited pattern image can be generated when printing/outputting content data, and thus the color of the copy-forgery-inhibited pattern image, as well as the characters or the like that are to be visualized when the original document is duplicated, can be set with freedom. There is a further advantage in that the output time, information unique to the printing device, and so on can be used in the copy-forgery-inhibited pattern image.
As described above, such a copy-forgery-inhibited pattern image achieves the effect of suppressing the use of duplicates, as predetermined characters or the like that could not be recognized prior to duplication appear when the original document is duplicated. In order to achieve this effect, the generated copy-forgery-inhibited pattern image is fundamentally configured of two regions: a region where the same image present in the original document remains in the duplicate; and a region where the image present in the original document disappears in the duplicate or appears lighter compared to the stated remaining image. With such a copy-forgery-inhibited pattern image configured of two regions, it is preferable for the stated two regions to have approximately the same density when printed and outputted.
In other words, it is necessary for the printed/outputted copy-forgery-inhibited pattern image to be composed so that the characters that are visualized in the duplicate are hidden and difficult to recognize visually by a human on a macro scale. Such an image region, which is hidden in the printed output that includes the copy-forgery-inhibited pattern image that appears, visually recognizable to humans, in a duplicate resulting from that printed output being duplicated, is called a “latent image”. Furthermore, an image region that disappears in the duplicate or is less dark compared to the latent image visualized in the duplicate is called a “background” (or a “background image”), for the sake of convenience. The copy-forgery-inhibited pattern image is, basically speaking, made up of the latent image and the background image. Note that there are also cases where the latent image is called a “foreground” when discussing user interfaces.
The latent image is composed of a concentration of dots within a predetermined region. As opposed to this, the background part is composed of dots dispersed throughout a predetermined region. It is possible to make it difficult to distinguish between the latent image part and the background part in the printed output including the copy-forgery-inhibited pattern image by making the density of the dots approximately the same within these regions.
FIG. 10 is a diagram illustrating the state of the dots in the two image regions, or the latent image part and the background part. As illustrated in FIG. 10, a copy-forgery-inhibited pattern image is composed of a background part in which dots are dispersed throughout a predetermined region and a latent image part in which dots are concentrated within a predetermined region. The dots within these two regions can be generated through halftone processes, dithering processes, and the like that differ from one another. For example, when generating a copy-forgery-inhibited pattern image using halftone processing, a halftone process that utilizes low lines per inch in the latent image part is carried out. Meanwhile, it is preferable to carry out a halftone process that applies high lines per inch to the background part.
Furthermore, when generating a copy-forgery-inhibited pattern image using a dithering process, it is preferable to carry out a dithering process using a dot-concentrated dithering matrix on the latent image part, and carry out a dithering process using a dot-dispersed dithering matrix on the background part.
There is generally a limit level on the reproduction capabilities of the scanning and image forming units of a copy machine. This limit level depends on the input resolution at which minute dots in an original document are scanned and the output resolution at which those minute dots are reproduced. When the dots in the background part of the copy-forgery-inhibited pattern image are formed so as to be smaller than the limit level at which a copy machine can reproduce those dots, and the dots in the latent image part of the copy-forgery-inhibited pattern image are formed so as to be larger than the stated limit level, the dots of the latent image part are reproduced in the duplicate, whereas the small dots of the background part are not reproduced. Using this characteristic makes the latent image appear in a duplicate in which the copy-forgery-inhibited pattern image has been duplicated. An image appearing in the duplicate shall be referred to as ‘visualization’ hereinafter. Note that even if the background part has been reproduced through the duplication, similar effects can be achieved as in the case where the dots are not reproduced, as long as the latent image part is a level that can be obviously recognized level in the duplicate.
FIGS. 11A and 11B are diagrams illustrating an image that has been visualized in a duplicate, and conceptually illustrates visualization in the duplicate where the dots have been concentrated, and a lack of reproduction in the duplicate where the dots have been dispersed.
It should be noted that copy-forgery-inhibited pattern printing is not limited to the stated configuration; any configuration may be used as long as the character string or the like is reproduced at a recognizable level in the duplicate. In other words, copy-forgery-inhibited pattern printing in which the character string or the like is set to be the background part and thus appears as knockout characters when duplicated also achieves the same effect.
There is another advantage in that the output time, information unique to the printing device, and so on can be used as the copy-forgery-inhibited pattern image. In particular, there are situations where a character string image visualizing the computer name is used, as information unique to the device that generated the print job. This computer name is then used to identify the printing conditions.
However, the following problems arise due to fluctuations in the printing condition information (particularly, information for identifying items), and the computing environment.
Information such as usernames, computer names, and so on set to be the visualized image in the copy-forgery-inhibited pattern is called “variable information”. The word “variable” is used here because even if a “username”, “date and time”, or the like is set using an operational section, finalization of the details of the character string occurs when the copy-forgery-inhibited pattern is generated. Thus the username, print time, and the like from when the printing occurs become the finalized character string. On the other hand, “custom” represents information that not variable, and the content of the character string is finalized when the character string is inputted using the operational section.
A user specifies variable information such as a “username”, “computer name”, or the like; that information becomes the latent image character string in the copy-forgery-inhibited pattern, and is used to identify the printing conditions. The finalization of the details occurs when the copy-forgery-inhibited pattern is generated. Thus far, the “username”, “computer name”, and the like have been acquired by a single computer with which the printing is executed and the copy-forgery-inhibited pattern is generated, and thus there have been no problems (see FIG. 13). In other words, information such as the “username” and “computer name” has been paired with a single person or item.
However, user environments have become diverse, and the need for server-integrated computing, as exemplified by the Metaframe scheme, has arisen. In such a server-integrated computing environment, a user logs on to a server via a terminal and uses that server and its resources. An example of the procedure through which a user uses the server/resources shall be provided hereinafter.
The user starts up his/her own client computer (terminal), or in other words, logs on to the terminal and launches the terminal software. The user then logs on to the integrated server via the terminal, and uses server processes. In this example, the user is logging on twice, accessing two computers, and the processing is being performed by the server (see FIG. 14).
In this server-integrated environment, the “username”, “computer name”, and the like are acquired. As described above, this processing is performed on the server side. The acquired “username” is the name used to log on to the server, and thus the identifiability can be maintained; however, the “computer name” is the server name, and thus is information that has low identifiability.
In other words, in such an environment, information such as the “username” and “computer name” is not paired with a single person or item. In order to maintain the identifiability of the “computer name” in such an integrated environment, it is necessary to reflect the computer names of terminals not carrying out printing processing in the printing process performed by the server.
Moreover, IP addresses, MAC addresses, and so on, which are pieces of variable information carrying similar meanings as the stated “computer name”, have identifiability problems in such an integrated environment. However, the situation is not such that identifiability is lacking in all types of variable information. Even in such an integrated environment, a “job name” is not problematic in terms of identifiability as it indicates the same spool file.
Variable information and extensions for control thereof is thus desirable when considering such server integration and future virtual server environments. Processing for cases where an item is not paired with a single piece of information is also necessary. Accordingly, when taking the usability for the user into consideration, it is desirable for the program that carries out such processing to automatically select processes in accordance with the environment in which the system is present. Of course, manual settings should also be possible.